Electrical regulator



Da 36, 1947. H. G. HAAS ET AL ELECTRICAL REGULATOR Fi led Jan. 123, i945ENVENTORS Harold C. Haas riiiizlfif I aalalaL t2: Jamkzou hsefi R RussoPatented Dec. 16, 1 947 ELECTRICAL REGULATOR Harold G. Haas, Bellevllle.and Joseph P. Russo. Bloomfield, N. 1., minors to Bendix AviationCorporation. Teterboro. N. L. a corporation of Delaware ApplicationJanuary 23, 1845, Serial No. 574,113

' 1 ,Claim. (Cl. I ll-228) Our present invention relates to electricalregulators and more particularly to a novel electrical system wherebyhunting of the regulator may be reduced and a controlled voltagemaintained at a desired value.

An object of the invention is to provide a novel voltage regulatingsystem for maintaining constant line voltage under changing loadconditions.

Another object of the invention is to provide novel means for effectinganti-hunt characteristics in a voltage regulator.

Another object of the invention is to provide novel means for utilizingin an electric device for regulating the output of a generator, the lagsv in the control circuit of the generator for differentially timing thefollow-up and reset responses of the regulator.

These and other objects and features of the invention are pointed out inthe following description in terms of the embodiment thereof which isshown in the accompanying drawing. It is to be understood-however, thatthe drawing is for the purpose of illustration only, and is not designedas a definition of the limits of the invention. reference being had tothe appended claim for this purpose.

The drawing in a diagrammatic view illustratinga control systemembodying one form of our invention.

In the form of the invention shown in the drawing'there is provided adirect current generator of conventional type and indicated generally bythe numeral i. v

The generator i has an armature winding, not shown, but which may be ofconventional type. Connections from the armature winding lead to acommutator 2 having brushes 8 and electrical connections leading tooutput lines and 8, to

which there is applied by the generator i a negative and positivepotential respectively. The generator i has an exciter field winding 8connected at one end to the output line 8 by an electrical conductor 8which also leads to a terminal A- of a generator set. Theopposite end ofthe exciter field winding 8 is connected by a suitable electricalconductor to a terminal F+ of the generator set. g

The output of the generator i is controlled by regulating the excitationof the field winding 8 in a manner which will be hereinafter explained.The output of the direct current generator i is also connected throughelectrical conductors i8 and II to brushes l4 and I5 riding on sliprings i8 and il respectively,- which may be mounted on the drive'shaftflhe generator i.

2 indicated by dotted line. The slip rings it and I! are connectedthrough. electrical conductors i8 and I8 to an exciting field 2i of analternator having stator windings indicated generally by the numeral 28.The exciting field winding 2i may be mounted on the same drive shaft asthe armature 2 and may be rotated in relation to the stator windings 28,so as to induce an alternating current in the stator windings 28 havinga value dependent upon the excitation of the winding 2 i.

The shaft for rotating the armature 2 and exciting field winding 2|maybe driven through a suitable constant speed drive from the aircraftengine or other suitable power source.

The stator windings 23 may have windings 25.

2G, and 21 grounded at one end thereof through electrical conductor 28.v

The windings 25, 26 and .21 are connected to terminals A, B and C of thegenerator set and through suitable electrical conductors ill, 3! and 32to stator windings 86, 81 and 88 respectively. of a suitable alternatingcurrent load 48, such as an alternating current motor or other suitableload means. The windings 36. 3'! and 38. are grounded through anelectrical conductor 4|.

The excitationof the exciter field winding 8 is controlled preferably bya variable resistance carbon pile element 45 connected at one end by anelectrical conductor to a terminal D of a control unit and from whichterminal leads an electrical conductor 48 to the terminal A+ of thegenerator set. The terminal A+ is connected to the positive side of thegenerator through the conductor 8. The opposite end of the variableresistance! is connected by an electrical conductor to a terminal K ofthe control unit. A seond conductor leads from the terminal K to winding58 of the control unit. The'opposite end of the winding is connected toa terminal C and the winding 50 is connected in series with the exciterfield winding 8 through a conductor 5i leading from the terminal C tothe terminal F-{-- of the generator set. Thus the variable resistancecarbon pile element 45, winding 50,

.oi. a control winding 15.

There is connected to the conductor I at it.

an electrical conductor OI which leads to a terminal B the control unit.A resistance winding II is connected at one end to the terminal B and atthe opposite end to a variable resistance element 82 having a manuallyadjustable arm I for adjusting the resistance thereoi. ior calibrationpurposes. The arm Cl 0! the adjustable resistance i2 is connectedthrough an electrical conductor st to a junction oi a rectifier bridge86. The opposite junction of the rectifier bridge 66 is connectedthrough a suitable electrical conductor 88 to a terminal A of thecontrol unit. Leading from the terminal A is an electrical conductor 10which is connected at H to the conductor 3|. Output conductors II and I3of the rectifier bridge 66 are connected to opposite ends As to thislatter arrangement, it will be readily seen that the winding Itconnected through the single phase bridge type rectifier 80 is energizedin response to the voltge output across the output lines 30 and 3! ofthe alternator 23.

The windings 50, I! and I! provide electromagnetic means which are soarranged in a carbon pile regulator as to control an armature 18 andthereby the pressure applied to the carbon pile 45, as will be explainedhereinafter. The regulator is shown diagrammatically in the drawing asincluding an armature l8 pivoted at 11 and exerting a compressive forceupon the carbon pile 45 under tension of a spring I8. The spring 18 isarranged so as to balance the pull on the armature by the electromagnetII when energized by a line voltage havinga predetermined value and ispreferably of a type such as shown in the patent application Serial No.570,002 of William G. Neild filed December 27, 1944, now U. S. PatentNo. 2,427,805, granted September 23, 1947 and assigned to BendixAviation Corporation.

Thus as explained in greater detail in the latter application, theregulator is arranged so as to maintain a substantially constant outputvoltage in the lines Ill, II and I! under varying load conditions.

In the arrangement of the drawing, the windings 50, 55 and Il are eacharranged in relation to the carbon pile regulator so as to apply anelectromagnetic force upon the armature 18 controlling the carbon pile.

The winding ll connected across the rectifier 68 provides the maincontrol for the carbon pile l and governs the regulation thereof inaccordance with voltage of the lines SI and ii.

The series winding Bl connected in series with the carbon pile ll, has atime constant difierentfrom windings! and SI and reacts more rapidlythan either b1 these windings and practically immediately on the carbonpile 45 upon a change in the energization thereof so as to tend toprovide a definite; low sensitivity or ratio between exclter fieldcurrent change and lines 30 and 3| voltage change. The winding ll mayfor example have only about fifty turns of wire efi'ecting a relativelylow resistance.

The limiting action or the winding II is counteracted by the shuntwinding II which prowinding II, but slower in response to change thanwinding ll.

In the form of the invention disclosed here-.in,thewindingllissoarrangedastoaddto the electromagnetic iorce producedby the winding ll. However, the winding II is arranged tocounter-balance the electromagnetic force due to the winding ll. Hencethe electromagnetic force due to the winding ll subtracts iron the totaldue to the windings II and Ill. The winding 55 is constructed to have aconsiderably larger time constant than the windings I and II together inseries with the result that it does not interfere with the prompti'ollow-up action due to the winding Ill. but provides a more gradualreset of this follow-up. The currents in the windings 50 and II arepreferably of the order respectively of amperes and milliamperes.

Thus, it will be seen that upon an increase in the load applied to theoutput lines 30 and II the voltage will decrease, causing theelectromagnet I5 to adjust the carbon pile I so as to decreasethelatter's resistance. Such decrease in resistance will increase thecurrent flow through the windings ill and BI. The winding 50 being morerapid in its response to current change tends to increase the totalelectromagnetic force, and thereby to limit the adjustment of the carbonpile in a resistance-decreasing direction so that this follow-up actionprevents the carbon pile from over-adjustment. The winding II moreslowly responds to change of potential across the field winding U so asto counter-balance the eilect of winding 50 causing a desirable resetaction tending to free the regulator from load error. Upon a decrease inthe load applied to output lines Ill and II, an opposite action willtake eiiect in which the windings I and II will exert a stabilizingeflect.

Although only one embodiment of the invention has been illustrated anddescribed, various changes in the forms and relative arrangements of theparts. which will now appear to those skilled in the art, may be madewithout departing from the scope oi the invention, reference being hadto the appended claim for a definition of the limits 01 the invention.

What is claimed is:

A line voltage regulating system for a generator supplying line currentto a variable load and including an exciter field comprising, a carbonpile, an armature operatively connected thereto for varying theelectrical resistance'oi' said carbon pile, a spring biasing a portionof the armature to tend to adjust said carbon pile up promptly limitingthe change of resistance of said carbon pile upon a chan e in the linevolt- 6 age, a. third electromagnetic winding connected 1 across theexciter field winding and having a. time REFERENCES CITED constantsubstantially greater than said second The following references are ofrecord in the winding so as to provide a slower response than file Ofthis Patent! said second winding and exciter field in series 5 UNITEDSTATES PATENTS to change in the resistance of said carbon pile, and saidthird winding arranged in opposition Number Name Date to the first andsecond windings so a to substan- 2,298,536 Logan Oct. 13, 1942 tiallyeliminate the stated follow-up action of said 1,146,925 Conrad July 2191 secondwinding in a relatively retarded manner. 10

-' HAROLD G. HAAS.

JOSEPH P. RUSSO.

